Chapter 27 - Avoiding Blunders

Abstract

This chapter presents several mistakes in pumping station design that could be minimized by making periodic design reviews at various stages of design and acquiring extensive knowledge about the manufactured products and pumping station design. One of the mistakes is inadequate ventilation for control rooms containing AFD equipment. Consideration of the effect of the heat loads from AFD equipment in designing and sizing the ventilating and air-conditioning systems for such electrical control rooms is required. The presence of hydraulic resonance within a pumping system could result in very high-pressure pulsations, high vibration, loud noises, and premature failure of the pump and/or piping equipment. The best way to avoid hydraulic resonance is to calculate the expected resonance frequency while the piping system is being designed and make sure that it is well away from the vane-pass frequency of the selected pump. Wastewater systems are especially vulnerable to water hammer because of buildup of grease and foam in control devices such as air valves. Pilot-operated surge-control valves for wastewater are unreliable due to the potential clogging of pilot lines, so it is recommended to avoid them in wastewater pumping stations. The water hammer is to be avoided in wastewater force mains by controlling the pipeline profile and/or by adding flywheels to drivers.